Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "nsJPEGEncoder.h"
#include "prprf.h"
#include "nsString.h"
#include "nsStreamUtils.h"
#include "gfxColor.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/UniquePtrExtensions.h"
extern "C" {
#include "jpeglib.h"
}
#include <setjmp.h>
#include "jerror.h"
using namespace mozilla;
NS_IMPL_ISUPPORTS(nsJPEGEncoder, imgIEncoder, nsIInputStream,
nsIAsyncInputStream)
class nsJPEGEncoderInternal {
friend class nsJPEGEncoder;
protected:
/**
* Initialize destination. This is called by jpeg_start_compress() before
* any data is actually written. It must initialize next_output_byte and
* free_in_buffer. free_in_buffer must be initialized to a positive value.
*/
static void initDestination(jpeg_compress_struct* cinfo);
/**
* This is called whenever the buffer has filled (free_in_buffer reaches
* zero). In typical applications, it should write out the *entire* buffer
* (use the saved start address and buffer length; ignore the current state
* of next_output_byte and free_in_buffer). Then reset the pointer & count
* to the start of the buffer, and return TRUE indicating that the buffer
* has been dumped. free_in_buffer must be set to a positive value when
* TRUE is returned. A FALSE return should only be used when I/O suspension
* is desired (this operating mode is discussed in the next section).
*/
static boolean emptyOutputBuffer(jpeg_compress_struct* cinfo);
/**
* Terminate destination --- called by jpeg_finish_compress() after all data
* has been written. In most applications, this must flush any data
* remaining in the buffer. Use either next_output_byte or free_in_buffer
* to determine how much data is in the buffer.
*/
static void termDestination(jpeg_compress_struct* cinfo);
/**
* Override the standard error method in the IJG JPEG decoder code. This
* was mostly copied from nsJPEGDecoder.cpp
*/
static void errorExit(jpeg_common_struct* cinfo);
};
// used to pass error info through the JPEG library
struct encoder_error_mgr {
jpeg_error_mgr pub;
jmp_buf setjmp_buffer;
};
nsJPEGEncoder::nsJPEGEncoder()
: mFinished(false),
mImageBuffer(nullptr),
mImageBufferSize(0),
mImageBufferUsed(0),
mImageBufferReadPoint(0),
mCallback(nullptr),
mCallbackTarget(nullptr),
mNotifyThreshold(0),
mReentrantMonitor("nsJPEGEncoder.mReentrantMonitor") {}
nsJPEGEncoder::~nsJPEGEncoder() {
if (mImageBuffer) {
free(mImageBuffer);
mImageBuffer = nullptr;
}
}
// nsJPEGEncoder::InitFromData
//
// One output option is supported: "quality=X" where X is an integer in the
// range 0-100. Higher values for X give better quality.
//
// Transparency is always discarded.
NS_IMETHODIMP
nsJPEGEncoder::InitFromData(const uint8_t* aData,
uint32_t aLength, // (unused, req'd by JS)
uint32_t aWidth, uint32_t aHeight, uint32_t aStride,
uint32_t aInputFormat,
const nsAString& aOutputOptions) {
NS_ENSURE_ARG(aData);
// validate input format
if (aInputFormat != INPUT_FORMAT_RGB && aInputFormat != INPUT_FORMAT_RGBA &&
aInputFormat != INPUT_FORMAT_HOSTARGB)
return NS_ERROR_INVALID_ARG;
// Stride is the padded width of each row, so it better be longer (I'm afraid
// people will not understand what stride means, so check it well)
if ((aInputFormat == INPUT_FORMAT_RGB && aStride < aWidth * 3) ||
((aInputFormat == INPUT_FORMAT_RGBA ||
aInputFormat == INPUT_FORMAT_HOSTARGB) &&
aStride < aWidth * 4)) {
NS_WARNING("Invalid stride for InitFromData");
return NS_ERROR_INVALID_ARG;
}
// can't initialize more than once
if (mImageBuffer != nullptr) {
return NS_ERROR_ALREADY_INITIALIZED;
}
// options: we only have one option so this is easy
int quality = 92;
if (aOutputOptions.Length() > 0) {
// have options string
const nsString qualityPrefix(u"quality="_ns);
if (aOutputOptions.Length() > qualityPrefix.Length() &&
StringBeginsWith(aOutputOptions, qualityPrefix)) {
// have quality string
nsCString value = NS_ConvertUTF16toUTF8(
Substring(aOutputOptions, qualityPrefix.Length()));
int newquality = -1;
if (PR_sscanf(value.get(), "%d", &newquality) == 1) {
if (newquality >= 0 && newquality <= 100) {
quality = newquality;
} else {
NS_WARNING(
"Quality value out of range, should be 0-100,"
" using default");
}
} else {
NS_WARNING(
"Quality value invalid, should be integer 0-100,"
" using default");
}
} else {
return NS_ERROR_INVALID_ARG;
}
}
UniquePtr<uint8_t[]> rowptr;
if (aInputFormat == INPUT_FORMAT_RGBA ||
aInputFormat == INPUT_FORMAT_HOSTARGB) {
rowptr = MakeUniqueFallible<uint8_t[]>(aWidth * 3);
if (NS_WARN_IF(!rowptr)) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
jpeg_compress_struct cinfo;
// We set up the normal JPEG error routines, then override error_exit.
// This must be done before the call to create_compress
encoder_error_mgr errmgr;
cinfo.err = jpeg_std_error(&errmgr.pub);
errmgr.pub.error_exit = nsJPEGEncoderInternal::errorExit;
// Establish the setjmp return context for my_error_exit to use.
if (setjmp(errmgr.setjmp_buffer)) {
// If we get here, the JPEG code has signaled an error.
// We need to clean up the JPEG object, close the input file, and return.
return NS_ERROR_FAILURE;
}
jpeg_create_compress(&cinfo);
cinfo.image_width = aWidth;
cinfo.image_height = aHeight;
cinfo.input_components = 3;
cinfo.in_color_space = JCS_RGB;
cinfo.data_precision = 8;
jpeg_set_defaults(&cinfo);
jpeg_set_quality(&cinfo, quality, 1); // quality here is 0-100
if (quality >= 90) {
int i;
for (i = 0; i < MAX_COMPONENTS; i++) {
cinfo.comp_info[i].h_samp_factor = 1;
cinfo.comp_info[i].v_samp_factor = 1;
}
}
// set up the destination manager
jpeg_destination_mgr destmgr;
destmgr.init_destination = nsJPEGEncoderInternal::initDestination;
destmgr.empty_output_buffer = nsJPEGEncoderInternal::emptyOutputBuffer;
destmgr.term_destination = nsJPEGEncoderInternal::termDestination;
cinfo.dest = &destmgr;
cinfo.client_data = this;
jpeg_start_compress(&cinfo, 1);
// feed it the rows
if (aInputFormat == INPUT_FORMAT_RGB) {
while (cinfo.next_scanline < cinfo.image_height) {
const uint8_t* row = &aData[cinfo.next_scanline * aStride];
jpeg_write_scanlines(&cinfo, const_cast<uint8_t**>(&row), 1);
}
} else if (aInputFormat == INPUT_FORMAT_RGBA) {
MOZ_ASSERT(rowptr);
uint8_t* row = rowptr.get();
while (cinfo.next_scanline < cinfo.image_height) {
ConvertRGBARow(&aData[cinfo.next_scanline * aStride], row, aWidth);
jpeg_write_scanlines(&cinfo, &row, 1);
}
} else if (aInputFormat == INPUT_FORMAT_HOSTARGB) {
MOZ_ASSERT(rowptr);
uint8_t* row = rowptr.get();
while (cinfo.next_scanline < cinfo.image_height) {
ConvertHostARGBRow(&aData[cinfo.next_scanline * aStride], row, aWidth);
jpeg_write_scanlines(&cinfo, &row, 1);
}
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
mFinished = true;
NotifyListener();
// if output callback can't get enough memory, it will free our buffer
if (!mImageBuffer) {
return NS_ERROR_OUT_OF_MEMORY;
}
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::StartImageEncode(uint32_t aWidth, uint32_t aHeight,
uint32_t aInputFormat,
const nsAString& aOutputOptions) {
return NS_ERROR_NOT_IMPLEMENTED;
}
// Returns the number of bytes in the image buffer used.
NS_IMETHODIMP
nsJPEGEncoder::GetImageBufferUsed(uint32_t* aOutputSize) {
NS_ENSURE_ARG_POINTER(aOutputSize);
*aOutputSize = mImageBufferUsed;
return NS_OK;
}
// Returns a pointer to the start of the image buffer
NS_IMETHODIMP
nsJPEGEncoder::GetImageBuffer(char** aOutputBuffer) {
NS_ENSURE_ARG_POINTER(aOutputBuffer);
*aOutputBuffer = reinterpret_cast<char*>(mImageBuffer);
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::AddImageFrame(const uint8_t* aData, uint32_t aLength,
uint32_t aWidth, uint32_t aHeight,
uint32_t aStride, uint32_t aFrameFormat,
const nsAString& aFrameOptions) {
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsJPEGEncoder::EndImageEncode() { return NS_ERROR_NOT_IMPLEMENTED; }
NS_IMETHODIMP
nsJPEGEncoder::Close() {
if (mImageBuffer != nullptr) {
free(mImageBuffer);
mImageBuffer = nullptr;
mImageBufferSize = 0;
mImageBufferUsed = 0;
mImageBufferReadPoint = 0;
}
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::Available(uint64_t* _retval) {
if (!mImageBuffer) {
return NS_BASE_STREAM_CLOSED;
}
*_retval = mImageBufferUsed - mImageBufferReadPoint;
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::StreamStatus() {
return mImageBuffer ? NS_OK : NS_BASE_STREAM_CLOSED;
}
NS_IMETHODIMP
nsJPEGEncoder::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
}
NS_IMETHODIMP
nsJPEGEncoder::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
uint32_t aCount, uint32_t* _retval) {
// Avoid another thread reallocing the buffer underneath us
ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
uint32_t maxCount = mImageBufferUsed - mImageBufferReadPoint;
if (maxCount == 0) {
*_retval = 0;
return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
}
if (aCount > maxCount) {
aCount = maxCount;
}
nsresult rv = aWriter(
this, aClosure,
reinterpret_cast<const char*>(mImageBuffer + mImageBufferReadPoint), 0,
aCount, _retval);
if (NS_SUCCEEDED(rv)) {
NS_ASSERTION(*_retval <= aCount, "bad write count");
mImageBufferReadPoint += *_retval;
}
// errors returned from the writer end here!
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::IsNonBlocking(bool* _retval) {
*_retval = true;
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
uint32_t aRequestedCount, nsIEventTarget* aTarget) {
if (aFlags != 0) {
return NS_ERROR_NOT_IMPLEMENTED;
}
if (mCallback || mCallbackTarget) {
return NS_ERROR_UNEXPECTED;
}
mCallbackTarget = aTarget;
// 0 means "any number of bytes except 0"
mNotifyThreshold = aRequestedCount;
if (!aRequestedCount) {
mNotifyThreshold = 1024; // 1 KB seems good. We don't want to
// notify incessantly
}
// We set the callback absolutely last, because NotifyListener uses it to
// determine if someone needs to be notified. If we don't set it last,
// NotifyListener might try to fire off a notification to a null target
// which will generally cause non-threadsafe objects to be used off the
// main thread
mCallback = aCallback;
// What we are being asked for may be present already
NotifyListener();
return NS_OK;
}
NS_IMETHODIMP
nsJPEGEncoder::CloseWithStatus(nsresult aStatus) { return Close(); }
// nsJPEGEncoder::ConvertHostARGBRow
//
// Our colors are stored with premultiplied alphas, but we need
// an output with no alpha in machine-independent byte order.
//
// See gfx/cairo/cairo/src/cairo-png.c
void nsJPEGEncoder::ConvertHostARGBRow(const uint8_t* aSrc, uint8_t* aDest,
uint32_t aPixelWidth) {
for (uint32_t x = 0; x < aPixelWidth; x++) {
const uint32_t& pixelIn = ((const uint32_t*)(aSrc))[x];
uint8_t* pixelOut = &aDest[x * 3];
pixelOut[0] = (pixelIn & 0xff0000) >> 16;
pixelOut[1] = (pixelIn & 0x00ff00) >> 8;
pixelOut[2] = (pixelIn & 0x0000ff) >> 0;
}
}
/**
* nsJPEGEncoder::ConvertRGBARow
*
* Input is RGBA, output is RGB, so we should alpha-premultiply.
*/
void nsJPEGEncoder::ConvertRGBARow(const uint8_t* aSrc, uint8_t* aDest,
uint32_t aPixelWidth) {
for (uint32_t x = 0; x < aPixelWidth; x++) {
const uint8_t* pixelIn = &aSrc[x * 4];
uint8_t* pixelOut = &aDest[x * 3];
uint8_t alpha = pixelIn[3];
pixelOut[0] = gfxPreMultiply(pixelIn[0], alpha);
pixelOut[1] = gfxPreMultiply(pixelIn[1], alpha);
pixelOut[2] = gfxPreMultiply(pixelIn[2], alpha);
}
}
void nsJPEGEncoder::NotifyListener() {
// We might call this function on multiple threads (any threads that call
// AsyncWait and any that do encoding) so we lock to avoid notifying the
// listener twice about the same data (which generally leads to a truncated
// image).
ReentrantMonitorAutoEnter autoEnter(mReentrantMonitor);
if (mCallback &&
(mImageBufferUsed - mImageBufferReadPoint >= mNotifyThreshold ||
mFinished)) {
nsCOMPtr<nsIInputStreamCallback> callback;
if (mCallbackTarget) {
callback = NS_NewInputStreamReadyEvent("nsJPEGEncoder::NotifyListener",
mCallback, mCallbackTarget);
} else {
callback = mCallback;
}
NS_ASSERTION(callback, "Shouldn't fail to make the callback");
// Null the callback first because OnInputStreamReady could reenter
// AsyncWait
mCallback = nullptr;
mCallbackTarget = nullptr;
mNotifyThreshold = 0;
callback->OnInputStreamReady(this);
}
}
/* static */
void nsJPEGEncoderInternal::initDestination(jpeg_compress_struct* cinfo) {
nsJPEGEncoder* that = static_cast<nsJPEGEncoder*>(cinfo->client_data);
NS_ASSERTION(!that->mImageBuffer, "Image buffer already initialized");
that->mImageBufferSize = 8192;
that->mImageBuffer = (uint8_t*)malloc(that->mImageBufferSize);
that->mImageBufferUsed = 0;
cinfo->dest->next_output_byte = that->mImageBuffer;
cinfo->dest->free_in_buffer = that->mImageBufferSize;
}
/* static */
boolean nsJPEGEncoderInternal::emptyOutputBuffer(jpeg_compress_struct* cinfo) {
nsJPEGEncoder* that = static_cast<nsJPEGEncoder*>(cinfo->client_data);
NS_ASSERTION(that->mImageBuffer, "No buffer to empty!");
// When we're reallocing the buffer we need to take the lock to ensure
// that nobody is trying to read from the buffer we are destroying
ReentrantMonitorAutoEnter autoEnter(that->mReentrantMonitor);
that->mImageBufferUsed = that->mImageBufferSize;
// expand buffer, just double size each time
uint8_t* newBuf = nullptr;
CheckedInt<uint32_t> bufSize =
CheckedInt<uint32_t>(that->mImageBufferSize) * 2;
if (bufSize.isValid()) {
that->mImageBufferSize = bufSize.value();
newBuf = (uint8_t*)realloc(that->mImageBuffer, that->mImageBufferSize);
}
if (!newBuf) {
// can't resize, just zero (this will keep us from writing more)
free(that->mImageBuffer);
that->mImageBuffer = nullptr;
that->mImageBufferSize = 0;
that->mImageBufferUsed = 0;
// This seems to be the only way to do errors through the JPEG library. We
// pass an nsresult masquerading as an int, which works because the
// setjmp() caller casts it back.
longjmp(((encoder_error_mgr*)(cinfo->err))->setjmp_buffer,
static_cast<int>(NS_ERROR_OUT_OF_MEMORY));
}
that->mImageBuffer = newBuf;
cinfo->dest->next_output_byte = &that->mImageBuffer[that->mImageBufferUsed];
cinfo->dest->free_in_buffer = that->mImageBufferSize - that->mImageBufferUsed;
return 1;
}
/* static */
void nsJPEGEncoderInternal::termDestination(jpeg_compress_struct* cinfo) {
nsJPEGEncoder* that = static_cast<nsJPEGEncoder*>(cinfo->client_data);
if (!that->mImageBuffer) {
return;
}
that->mImageBufferUsed = cinfo->dest->next_output_byte - that->mImageBuffer;
NS_ASSERTION(that->mImageBufferUsed < that->mImageBufferSize,
"JPEG library busted, got a bad image buffer size");
that->NotifyListener();
}
/* static */
void nsJPEGEncoderInternal::errorExit(jpeg_common_struct* cinfo) {
nsresult error_code;
encoder_error_mgr* err = (encoder_error_mgr*)cinfo->err;
// Convert error to a browser error code
switch (cinfo->err->msg_code) {
case JERR_OUT_OF_MEMORY:
error_code = NS_ERROR_OUT_OF_MEMORY;
break;
default:
error_code = NS_ERROR_FAILURE;
}
// Return control to the setjmp point. We pass an nsresult masquerading as
// an int, which works because the setjmp() caller casts it back.
longjmp(err->setjmp_buffer, static_cast<int>(error_code));
}